/Engine/Source/Runtime/Core/Public/GenericPlatform/GenericPlatformMisc.h
Return an ordered list of target platforms this runtime can support (ie Android_DXT, Android would mean that it prefers Android_DXT, but can use Android as well)
static void GetValidTargetPlatforms ( [TArray](API\Runtime\Core\Containers\TArray)< [FString](API\Runtime\Core\Containers\FString) > & TargetPlatformNames )